I won't be able to make the cottage legal rental without living in the primary home myself.

Signing the lease demonstrates they agree to the terms and then you can hold them accountable.If you don't do this, then the person named on the lease and paying the rent could disappear and you would have no legal authority to charge the remaining three for unpaid rent.

An LLC is useful for two things: anonymity and legal protection.

Do I have to legally disclose to my boss that I will have my sales agent license and have a brokerage sponsor that is someone different outside the MF development company?

Hello Doug, I am not a real estate attorney nor is this legal advice.Unless someone's state has specific laws banning contract assignments you should be fine doing the following.  

My humble advice to anyone attempting to do creative finance is:Creative finance is for experienced investors who have access to capital if anything goes wrong.Learn the lawsDon't use a contract "off the internet", laws vary by state and are also regulated on a federal levelLearn the financing techniques correctlyDon’t skip parts of the processDon’t ever do a “kitchen table” closingUse the proper deedAn attorney can help you with the legal work, but the rest you are on your ownYour guru will not bail you out“Investing” in someone else’s deal by providing a small 2nd loan so the “investor” can pay for “cash to the seller” and for “closing costs” so he can do the deal is a very bad planKnow what problems can ariseLearn the responses and solutions to problems before they are neededKnow everything there is to know about Title and what that meansKnow who a "protected class" individual isLearn the "back doors"Learn human natureUnderstand timelinesUnderstand regulation enforcement (some of these "mistakes" have a 10 year statue of limitations ( they can charge you 10 years AFTER you do the transaction) and carry hefty fines and possible imprisonmentThe court doesn't accept "I didn't know" for an answer"Know that the source of the lead plays a serious role in some states and federallyKnow how much of a "profit" pushes the boundaries to invite an investigationYou can be sued by the seller if you don’t do things correctlyYou are automatically at fault if an investigator or attorney or regulator gets involved.

It seemed like most the folks you have on staff are CPA or other, but no specific legal experts.

I am wondering if anyone has ever taken legal action against property managers, and if they think we have a potential case? 

The seller has the two lots legally separated, but due to deed restriction imposed by the subdivision development, found that building a house on the “tennis court” lot was not allowable. 

Seems like a messy situation.